Hello:)yes, it reveals the magic as you say. No wonder that many masterpieces (drawings or sculptures) are given the accolade of genius' artwork (Michel Angelo) because they were left "unfinished". That unfinished part of a piece of art lets the vieuwers' imagination "finish" the job. The perfect human brain is such that it enables people to feel perfectly what is suggested and not visually shown in a drawing or painting, or anything else!

This also works in your serie of drawings step by step; each unfinished stage works individually in an esthetic way and might be stronger than the final complete face that no longer leaves any room for the imagination because it imposes the whole head, completely built, as an entity.

Dear friend thank u. I tottaly agree with you. The great Da Vinci "fortunately" left us unfinished paintings where we can see not only the way of his progress but also reveals his greatness. (I' m not compare myself with Da Vinci of course).